Electromechanical interlock for laundry apparatus

ABSTRACT

Interlock for the door of a clothes washing machine or the like. The interlock is characterized by the provision of a solenoid-actuated door lock, which solenoid is operatively connected to a source of electrical power by means of a condition responsive structure and also by a manually operable switch. Energization of the solenoid serves to unlatch the door lock to thereby provide a &#39;&#39;&#39;&#39;fail-safe&#39;&#39;&#39;&#39; device, which can only be opened when the machine is not operating and by actuation of the manual operable switch.

United States Patent Inventor John D. Hughes Loudonville, Ohio App]. No. 807,712

Filed Mar. 17, 1969 Patented Aug. 31, 1971 Assignee Westinghouse Electric Corporation Pittsburgh, Pa.

ELECTROMECHANICAL INTERLOCK FOR LAUNDRY APPARATUS 2 Claims, 4 Drawing Figs.

US. Cl 68/12, 68/ 1 39 hit. Cl D061 33/02, D06f 39/14 Field of Search 68/12, 139; 134/57 DL, 58 DL; 4/292 [56] Rollerences Cited UNITED STATES PATENTS 3,065,619 11/1962 Coss 68/12 3,106,831 10/1963 Behrens 68/12 3,408,834 11/1968 McMillan 68/12 Primary Examiner-William I. Price AttorneysF. H. Henson, E. C. Arenz and B. B. Sklar, Jr.

device, which can only be opened when the machine is not operating and by actuation of the manual operable switch.

ELECTROMECHANICAL INTERLOCK FOR LAUNDRY APPARATUS BACKGROUND OF THE INVENTION This invention relates, in general, to laundry apparatus and, more particularly, to door lock structure therefor.

It is well known that commercial washing machines of the tumbler type utilize water which exceeds the level of the machine opening. This means that if the door is opened prematurely, a person could be scalded by the extremely hot water. There are also other hazardous conditions which exist, for example, during the water extraction part of the cycle when accessibility to the interior of the machine is prohibitive.

Accordingly, it is the general object of this invention to provide a new and improved clothes washing machine.

It is a more particular object of this invention to provide, in a clothes washing machine, an electromechanical door interlock, the purpose of which is not frustrated by an electrical power failure.

Another object of this invention is to provide a door lock for a washing machine which cannot be unlatched during operation of the machine or at preselected times during the operation of the machine.

BRIEF SUMMARY OF THE INVENTION Briefly, the above-cited objects are accomplished by the provision of a lock having a latch and catch arrangement wherein the latch is spring biased into a door locking position. A solenoid is provided for overriding the spring through the pivoting of a lever in response to energization of the solenoid. In order to provide a safety feature which prevents unlatching of the lock at any time during operation of the machine or during preselected times during the operation thereof, a timer-actuated switch is provided which is opened at the preselected times, consequently, the solenoid cannot be energized. A pushbutton switch is also provided which switch cooperates with the timer-actuated switch to permit energization of the door lock solenoid, closure of both switches, simultaneously, being required before the door can be opened.

In a modified form of the invention, a pressure-actuated switch is combined in circuitry with the timer-actuated and pushbutton switches such that the door unlock solenoid cannot be energized while water remains in the machine, even though operation of the machine has terminated.

Further objects and advantages of the present invention will become more apparent when considered in view of the drawings and detailed description forming a part hereof.

DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a clothes washing machine representing the invention;

FIG. 2 is a plan view of a latch arrangement employed for locking the door structure of the machine shown in FIG. 11;

FIG. 3 is a schematic of one form of interlock employed in the machine illustrated in FIG. 1; and

FIG. 4 is a schematic of a modified form of the invention shown in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, especially FIG. 1, reference character designates generally a clothes washing machine of the tumbler type (i.e. basket rotates about substantially horizontal axis). While the present description will be confined to a machine of this type, it will be appreciated that those machines which are referred to as top loading" may also employ the invention. Furthermore, the invention could be utilized in clothes dryers. The machine 10 comprises a body or shell 11 having attached thereto a service panel 12 and a top panel 13.

The machine 110 is provided with a fabric conditioner dispenser (not shown) which is accessible through a door 14 in the top panel 13. A detergent dispenser (also not shown) is accessible through a door 16 also carried by the top panel 13. The operation of the machine, being designed for use as a commercial unit, can only be varied insofar as the water temperature is concerned. To this end, there is provided an actuator knob 17. Other features which generally characterize the machine 10, are a coin meter 18 and a coin vault 19.

A door structure 21 supported for pivotal movement by a front wall 22 of the shell 11 provides access to the interior of the clothes basket (not shown). The door structure has a glass 23 mounted centrally thereof for viewing the interior of the washing machine during operation.

A door lock structure generally indicated at 24 (see FIG. 2) comprises a catch member 26 carried on the inside of the door structure 211. A latch housing 27 is mounted on the inside of the front wall 22 adjacent the catch 26. The latch housing has a transverse slot 28 which cooperates with a latch member 29 for movement from left to right and vice versa, as viewed in FIG. 2. The latch member 29 is operatively connected to a roll pin structure 31 which, in turn, is attached to a link latch or lever 32 pivotally supported by the latch housing 27. The latch member 29 is normally biased, by means of a spring 33, into locking engagement with the catch '26, that is, when the door structure 21 is in its closed position.

A solenoid 34 mounted on a bracket 36, carried by the front wall 22, is connected to the lever 32 by a spring 37. It will be appreciated that upward movement (as viewed in FIG. 2) of a plunger 38 of the solenoid 34 will effect pivoting of the lever 32 such that the latch will be moved out of engagement with the catch 26.

Energization of the solenoid 34 is accomplished, in accordance with the embodiment shown in FIG. 3, through closure of a pushbutton switch 39and the closure of a timeractuated switch 41. In the preferred mode of operation, the switch 41 is adapted to be closed by the timer only when the cycle of operation of the machine has terminated. It should be ap parent that the use of the spring 37 serves as a protective device which prevents the burning out of the solenoid 34, should the lock structure 24 become stuck.

In the embodiment shown in FIG. 4, there is provided a pressure switch 42 which is opened any time the machine contains water. In view of the foregoing description it will now be apparent that there has been provided an interlock for a clothes washing machine which interlock comprises a manually engaged latch and catch arrangement wherein the disengagement can only be accomplished through energization of a door unlock solenoid which solenoid requires the coincidence of at least three predetermined conditions, namely, an inoperative machine, the machine drained of water and the manual operation of a pushbutton switch.

Since numerous changes may be made in the above apparatus and different embodiments may be made without departing from the spirit thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Door interlock for a clothes washing machine having an access door to the washing apparatus and suitable circuitry including a timer for controlling the operation thereof, said interlock comprising:

a manually actuatable switch;

a timer-actuated switch;

movable means for normally locking said door when said door is in a closed position;

solenoid means connected to said locking means for moving said locking means to an unlocking position when said solenoid is actuated; and,

a fluid pressure switch serially connected to said solenoid with said manually actuable switch and said timer-actuated switch and moved from an open to a closed position 3 4 in response to the lenel Bf'th w ashing fluid within said sw imh is open whenever said washing maehine coniains Mishmachine being at least below said access door. ing fluid.

The door interlock of claim l yherein sq ig flniq pressure 

1. Door interlock for a clothes washing machine having an access door to The washing apparatus and suitable circuitry including a timer for controlling the operation thereof, said interlock comprising: a manually actuatable switch; a timer-actuated switch; movable means for normally locking said door when said door is in a closed position; solenoid means connected to said locking means for moving said locking means to an unlocking position when said solenoid is actuated; and, a fluid pressure switch serially connected to said solenoid with said manually actuable switch and said timer-actuated switch and moved from an open to a closed position in response to the level of the washing fluid within said machine being at least below said access door.
 2. The door interlock of claim 1 wherein said fluid pressure switch is open whenever said washing machine contains washing fluid. 